MFH: r458581

Fix builds of lang/gcc{48,49,5} with clang 6.0.0

Since clang++ 6.0.0 now defaults to -std=gnu++14 (similar to g++ 6 and
higher), building gcc48, gcc49 or gcc5 produce quite a number of
"invalid suffix on literal; C++11 requires a space between literal and
identifier" errors. This is because in many places, double quotes are
directly followed by printf helper macros like HOST_WIDE_INT_PRINT.

In gcc 6 and later, spaces were added between the double quotes and the
macros, to fix this issue, but for earlier versions, use a combination
of find, grep and sed to add them mechanically throughout the respective
source trees.

In addition, gcc5 needs a regular patch to fix an incorrect call to
error(), which should have been error_at(). (This was a mismerge by
upstream.)

Approved by: gerald (maintainer)
PR: 224927